Axle assembly

Abstract

Axle assemblies having a sensor of the mechanical input shaft type are difficult to access and subjected to radial and axial loads which cause premature failure. A connecting arrangement affixes a sensor body to a support bracket adjacent a second end of a rotatable spindle and maintains an input shaft of the sensor within a preselected range of axially aligned positions with respect to a spindle axis. A coupling arrangement couples the second end portion of the spindle to the input shaft and transfers only rotational motion from the spindle to the input shaft. The coupling arrangement permits a preselected amount of freedom of movement of the spindle relative to the sensor in axial and radial directions. Thus, damage to and premature failure of the sensor is alleviated and accessability is substantially improved. The axle assembly is particularly suited for use on an automatic guided vehicle.

We claim: 
     
       1. An axle assembly, comprising: a housing;   an output member having a first end and being rotatably connected to said housing;   a support bracket having first and second end portions and being connected at said first end portion to the first end of said output member, said second end portion having first and second spaced apart sides, and a bore opening at said sides;   a wheel;   a spindle having first and second end portions and a longitudinal spindle axis extending between said spindle end portions, said spindle being mounted in said bore and rotatable about said spindle axis, said spindle first end portion being connected to said wheel;   a sensor having a body and an input shaft rotatably connected to said body, said input shaft having a longitudinal axis;   means for connecting the sensor body to the second end portion of the support bracket at a location adjacent the second end portion of the spindle and maintaining the axis of the input shaft within a preselected range of axially aligned positions with respect to the axis of the spindle; and   means for coupling the second end portion of the spindle to the input shaft and transferring rotational motion from the spindle to the input shaft, said coupling means including a drive portion connected to said input shaft and engageable with said spindle, said drive portion being axially and radially movable relative to the spindle second end portion.   
     
     
       2. An axle assembly, comprising: a housing;   an output member having a first end and being rotatably connected to said housing;   a support bracket having first and second end portions and being connected at said first end portion to the first end of said output member, said second end portion having first and second spaced apart sides, and a bore opening at said sides;   a spindle having first and second end portions and a longitudinal spindle axis extending between said spindle end portions, said spindle being mounted in said bore and rotatable about said spindle axis;   a sensor having a body and an input shaft rotatably connected to said body, said input shaft having a longitudinal axis;   means for connecting the sensor body to the second end portion of the support bracket at a location adjacent the second end portion of the spindle and maintaining the axis of the input shaft within a preselected range of axially aligned positions with respect to the axis of the spindle; and   means for coupling the second end portion of the spindle to the input shaft and transferring rotational motion from the spindle to the input shaft, said coupling means including; a connecting member mounted on said input shaft;   a drive pin secured to said connecting member at a preselected radially spaced location from the axis of said input shaft, said drive pin extending from said connecting member in a direction substantially parallel to said input shaft axis; and   said spindle having an aperture disposed in the spindle second end portion, said drive pin being disposed in said aperture and engageable with said spindle in response to rotation of said spindle.     
     
     
       3. The axle assembly, as set forth in claim 2, wherein said connecting means includes: a carrier having a pilot portion and a support portion, said pilot portion being disposed in said support bracket bore adjacent the second side; and   a clamp having a flange and being connected to said support portion, said flange being engageable with the sensor body and adapted to secure the sensor body to said support portion.   
     
     
       4. The axle assembly, as set forth in claim 3, wherein said sensor body has a flange, said clamp flange being engageable with the sensor body flange, and said connecting means includes a plurality of fasteners screwthreadably connecting the clamp to said support portion. 
     
     
       5. The axle assembly, as set forth in claim 4, wherein said clamp flange is segmented. 
     
     
       6. The axle assembly, as set forth in claim 4, wherein said support portion has an aperture and said input shaft extends into the support portion aperture, said connecting means includes: a cover having an aperture and being connected to the support portion in an overlying relationship about the sensor; and   a conduit having a first end portion and being disposed in said cover aperture.   
     
     
       7. The axle assembly, as set forth in claim 2, including: a pair of antifriction bearings each having an outer race and an inner race, said inner races having a bore, said outer races being disposed, at spaced apart locations, in the bore of said support bracket, and said spindle being disposed in the bore of said inner races.   
     
     
       8. The axle assembly, as set forth in claim 7, wherein said spindle has a second end adjacent the spindle second end portion and wherein the aperture in the second end portion of the spindle opens at said spindle second end. 
     
     
       9. The axle assembly, as set forth in claim 8, wherein said connecting member has a bore, a threaded aperture opening in said bore, and a fastener screwthreadably engaged with said threaded aperture, said input shaft being disposed in the bore of said connecting member and engaged by said fastener, said fastener securing the input shaft to the connecting member. 
     
     
       10. The axle assembly, as set forth in claim 2, wherein said output member has an axis of rotation, an aperture disposed along said output member axis and opening at said first end, and including: a conduit having first and second end portions and being disposed in the aperture of said output member and extending past the first end of said output member, said conduit first end portion being connected to said connecting means; and   means for securing the conduit to said output member.   
     
     
       11. A steerable axle assembly, comprising: a housing;   an output member rotatably connected to said housing, said output member having a first end;   a support bracket having first and second end portions and being connected at said first end portion to the first end of said output member, said second end portion having first and second spaced apart sides and a bore disposed in said second end portion and opening at said first and second sides;   a spindle having first and second end portions, first and second opposed ends, and a longitudinal spindle axis extending between the first and second ends of said spindle, said spindle having an aperture disposed in the spindle second end portion and opening at the second end of the spindle;   means for rotatably mounting the spindle in the support bracket bore for rotation about said longitudinal spindle axis, said spindle first end portion being adapted to be connected to a ground engaging wheel, and said spindle second end portion being positioned adjacent the second side of said support bracket;   a sensor having a body and an input shaft rotatably connected to said body, said input shaft having a longitudinal axis and being rotatable about said input shaft longitudinal axis;   means for connecting the sensor body to the second end portion of the support bracket adjacent the support bracket second side and substantially aligning the longitudinal axis of the input shaft with the longitudinal axis of said spindle; and   a coupling having a driving portion and being mounted on said input shaft, said driving portion being radially spaced from said input shaft and axially disposed in said spindle aperture, said driving portion being movable in a circle about the input shaft axis in response to rotation of said spindle, said input shaft being rotatable about the input shaft axis in response to movement of the driving portion about said input shaft axis, said driving portion being free from connection with the second end portion of the spindle and contactably engaged by said spindle second end portion in response to rotation of the spindle.   
     
     
       12. The steerable axle assembly, as set forth in claim 11, wherein said coupling includes: a connecting member having a bore, said input shaft being disposed in the bore of said connecting member;   a fastener screwthreadably secured to said connecting member and engaged with said input shaft; and   a cylindrical pin being secured to said connecting member at a radially offset location relative to said input shaft axis, said cylindrical pin extending substantially parallel to said input shaft axis.   
     
     
       13. The steerable axle assembly, as set forth in claim 12, wherein said aperture is a cylindrical bore extending in a direction substantially parallel to said spindle axis. 
     
     
       14. The steerable axle assembly, as set forth in claim 13, wherein the cylindrical bore in the second end portion of the spindle has a preselected diameter, and said cylindrical pin has a preselected diameter, said diameter of the cylindrical bore being greater in magnitude than the diameter of the cylindrical pin. 
     
     
       15. The steerable axle assembly, as set forth in claim 11, wherein said connecting means includes: a carrier having a pilot portion and a support portion, said pilot portion being disposed in the bore of said support bracket at a location adjacent said second side, said support portion having an aperture and said sensor being positioned on said support portion with said input shaft disposed in the support portion aperture; and   a clamp having a flange and being connected to said support portion, said flange being engageable with said sensor body.   
     
     
       16. The steerable axle assembly, as set forth in claim 11, wherein said output member has an axis of rotation, a second end, and an aperture extending along said axis and opening at said first and second ends; and including: a conduit having first and second end portions and being disposed in the aperture of said output member, said conduit extending past said first and second output member ends and through said housing, said conduit first end portion being connected to the sensor body connecting means.   
     
     
       17. A work vehicle, comprising: a frame;   a steering mechanism having a housing, an output member, and a steering motor, said output member having first and second ends, a longitudinal axis extending past said first and second ends, and an aperture extending along said axis and opening at said ends, said output member being mounted in said housing and rotatable about said longitudinal axis, said motor being mounted on said housing and drivingly connected to said output member;   a support bracket having first and second end portions and being connected at said first end portion to the first end of said output member, said support bracket second end portion having first and second spaced apart sides, and a bore disposed in said second end portion and opening at said first and second sides;   a spindle having first and second opposed end portions and a longitudinal spindle axis extending between said spindle end portions, said spindle having an aperture opening at the second spindle end portion;   means for mounting the spindle in said bore for rotation about the longitudinal spindle axis, and locating said spindle first end portion adjacent the first side and said second spindle end portion adjacent the second side;   a wheel mounted on the first end portion of the spindle and rotatable with the spindle;   a sensor having a body and an input shaft rotatably connected to the body, said input shaft having a longitudinal input shaft axis and being rotatable about said axis;   a carrier having a pilot portion and a support portion, said pilot portion being disposed in said support bracket bore adjacent the second side;   means for connecting the sensor body to the carrier support portion and substantially axially aligning the axis of the input shaft with the axis of the spindle;   a cover connected to the support portion of the carrier and enclosing the sensor;   a coupling having a connecting member and a drive pin, said connecting member being mounted on said input shaft, said drive pin being affixed to said connecting member and radially spaced from said input shaft, said drive pin being axially disposed in said spindle aperture and movable in a circle about said input shaft in response to rotation of said spindle, said input shaft being rotatable about the input shaft axis in response to movement of the drive pin about said input shaft axis, said drive pin being free from connection with the second end portion of the spindle and contactably engaged by the spindle second end portion in response to rotation of the spindle; and   a conduit having first and second end portions and being disposed in the aperture of said output member, said conduit first end portion being connected to said cover and said conduit second end portion extending past the second end of said output member.